Excavating-cutter.



PATENTED DEC. 13, 1904.

J B. GANTWELL.

EXUAVATING CUTTER.

APPLICATION FILED JULY 5, 1904.

N0 MODEL.

my iESaEE: hm

NITE STATES Patented December 13, 1904.

PATENT OFFICE.

EXCAVfiTlNG-CUTTEH.

SPECIFICATION forming part of Letters Patent No. 777,180, dated December 13, 1904.

Application filed July 5, 1904. Serial No. 215,374. (No model.)

To all w/wm it may concern:

Be it known that I, JOHN BURKE CANTWELL, a citizen of the United States, residing at River Rouge, in the county of \Vayne and State of Michigan, have invented certain new and use ful Improvements in Excavating-Cutters, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention relates to excavating and dredging machines of that type in which the wet soil is loosened by a cutter and then carried away through a suction-pipe. Heret0 fore devices of this character have been used in which the end of the suction-pipe is provided with a rotary cutter having blades for paring the soil and directing it into the end of the suction-pipe. The greatest difficulty encountered with such machines as previously constructed is the tendency for the cutter to become clogged through the accumulation of mud or clay between the blades. To overcome this diificulty the present construction is designed; and the invention consists in the peculiar construction of the cutter-blades and the manner of securing the same to the rotary head, as hereinafter set forth.

In the drawings, Figure 1 is a sectional elevation of a cutter, the plane of section of the left half of said figure being on line 70 w and that of the right half on line e of Fig. 2. Fig. 2 is a section on line 3/ yfFig. 1; and Fig. 3 is a section through one of the blades on line .70 m, Fig. 1.

A is the suction-pipe, and B the rotary head at the end of said suction-pipe for supporting the cutter-blades. As shown, the head B is mounted upon the shaft G, which passes centrally through the suction-pipe and is journaled in a bearing ID therein. This construction, however, is not essential to the present invention, and, if desired, the cutter-head may be secured directly to the suction-pipe and the latter revolved.

he cutter comprises a series of blades E, each of which is of the following construction: a is the main portion of the blade, which eX- tends longitudinally of the cutter in the form of a stave. One edge of this blade is sharpened to form a cuttingedge, and the stave is space between blades.

inclined inwardly toward its rear edge, sothat the latter is nearer the center of rotation than the cutting edge of the adjacent stave. Asa consequence the rotation of the blade will cause any material encountered by the cutting edge to be deflected inwardly through the The forward end of the section a of the blade is bent to form an end portion 6, which extends inwardly and is secured to the rotary head B. This end portion is not only bent inwardly, but is also inclined to the plane of rotation. the angle of inclination being substantially the same as the angle of the body portion a to the radial plane of its cutting edge. Thus the end portions?) in their rotation will also direct the material severed inwardly between adjacent blades and into the space inclosed thereby communicating with the suction-pipe.

To secure the blades to the head B, the latter is provided with a series of radially-projecting lugs F, having their faces against which the blades bear inclined to the plane of rotation. These lugs are also beveled upon their opposite faces, so as to prevent forming an obstruction for the material passing between the blades. The blades may be secured to the lugs F by riveting, bolting, or any suitable means. The inner ends of the blades are preferably formed of similar shape to the outer ends, as shown, and are secured to the common supporting-ring Gr.

l/Vith the construction described it will be observed that the blades both in their longitudinal portions and end portions extend at substantially the same aiiigle to the path of rotation, and this angle is selected. so as to be most favorable for the clearance of the blades in the particular soil operated upon. It will be further noted that in cross-section the face over which the soil travels inwardly from its cutting edge is straight and without obstruction. The consequence is that in operation no part of the cutter will be clogged by wedging of the soil between blades, as in constructions heretofore employed.

The head B is preferably cupped or dished on its outer face, so that the blades E extend beyond the plane of the imperforated central 'portion of the head, and between this portion and the periphery are a series of apertures H, through which any loosened material at the end of the head may enter the suction-pipe.

In order that the strips of clay severed by the successive staves in their rotation may be further divided, I preferably provide a series of transverse cutters I, extending across the outer face of each stave. These cutters during the rotation of the head will sever the clay into small sections, which Will be more readily drawn through the suction-pipe.

What I claim as my invention is- 1. In a rotary excavating-cutter a blade having a longitudinally-extending portion and a radial end portion, said portions being sharpened at one edge thereof, and being inclined 3. The combination with a suction-pipe of a rotary cutter at the end thereof, comprising a revoluble head, radial lugs projecting therefrom, and a series of blades respectively secured to said lugs, each consisting of a longitudinal portion and a radial end portion, said portions being arranged to incline from their cutting edges at substantially the same angle to the path of rotation.

4:. The combination with a suction-pipe of a rotary cutter at the end thereof, comprising a revoluble cup-shaped head having radial projecting lugs and a series of cutting-blades having end portions secured to angling faces of said lugs, and longitudinally extending portions having a cutting edge continuous with that of said end portions, the face of each blade over which the severed material passes inward being straight in cross-section and at substantially the same angle to the path of travel throughout its extent.

5. In a rotary excavating-cutter the combination with a suction-pipe of a cutter comprising a series of longitudinally-extending blades and a series of transverse blades or cuttingribs on the outer faces of said longitudinal blades adapted to subdivide the strips of material severed by said blades.

In testimony whereof I aflix my signature in presence of two witnesses.

JOHN BURKE CANTWVELL.

Witnesses THAD. BARROW, OUs'rER SNYDER. 

